Pakistan began Eid in mourning Monday as the death toll from an oil tanker explosion rose to 153, with scores more injured after they were caught in a fireball while scooping up spilt fuel.

Dozens of grief-stricken relatives waited outside hospitals in Bahawalpur, the nearest major city to the disaster, to claim the bodies of their loved ones as Prime Minister Nawaz Sharif arrived to visit victims.

Around a dozen of them, carrying the blackened remains of two victims wrapped in white cloth on charpoys, tried to reach the prime minister in protest but were stopped by security personnel a few metres away.

"The day of Eid has become a day of mourning and pain for us," Sharif told the media outside Victoria Hospital, adding he has ordered an inquiry and compensation of two million rupees ($20,000) for the families of the dead, and one million rupees for the injured.

Eid al-Fitr, a normally joyous occasion, marks the end of the Muslim holy fasting month of Ramadan.

The tanker overturned early Sunday on a main highway from Karachi to Lahore while carrying some 40,000 litres of fuel. It exploded as crowds gathered to scavenge for fuel, ignoring warnings to stay away.

Police have said details remain unconfirmed, but cited witnesses who reported that a tyre on the tanker had burst.

The accident quickly drew scores of people from a nearby village, many armed with whatever containers they could find despite warnings from the driver and police of the danger.

Minutes later the tanker exploded, engulfing the crowd well as dozens of other vehicles in a massive fireball that sent a plume of thick smoke into the sky.

The tanker driver survived the crash and was later taken into custody.

"The death toll has climbed to 153, and many are in critical condition in various hospitals in Bahawalpur and Multan," Javed Iqbal, chief of Victoria Hospital, told AFP.

'We have been doomed'

Relatives waiting outside the hospital could not contain their grief.

Mumtaz Mai, a 40-year-old widow who lived with her two nephews, was beating her chest and screaming after both were lost in the fire.

"My world has come to an end," a weeping Mai told AFP, adding that they had been so badly burnt she was unable to recognise their bodies.

"Where will I go now, with whom will I live? My life is but a curse," she lamented.

Muhammad Ayub, in his early fifties, lost his brother and nephew.

"We have been doomed. How can we celebrate Eid and what would it mean to us when we cannot even recognise the dead bodies of our loved ones?" he asked.

Pakistanis were already grieving for at least 69 people killed in a series of militant attacks on Friday.

The country has an appalling record of fatal traffic accidents due to poor roads, badly maintained vehicles and reckless driving.

It has also long struggled to alleviate a chronic energy crisis, with regular blackouts crippling industry and exacerbating anger against the government.